This invention relates to dental preparations which provide highly desirable and unique effects particularly in the inclusion of materials having calcium and phosphate components or moieties.
Salts of calcium phosphates such as dicalcium orthophosphate dihydrate (DCPD), anhydrous dicalcium orthophosphate (ADCP) and calcium pyrophosphate have long been used in oral preparations such as toothpastes for the polishing and abrasive effects which they provide. Other materials containing calcium and phosphate, such as fluorapatite, have been disclosed for use in order to prevent caries. In particular, the article "Prevention of Dental Caries by Brushing the Teeth with Powders Containing Fluorapatite," McClendon and Foster, Journal of Dental Reasearch, Vol, 26, No. 3, July, 1947, pages 233-238, describes the use of an impure fluorapatite, powdered rock phosphate (71.4% fluorapatite), or a synthetic fluorapatite to reduce caries in vivo. The synthetic fluorapatite may be made by solution techniques of dropwise addition of lime water, orthophosphoric acid and sodium fluoride to distilled water or by adding alcohol and glycerine plus menthol or thymol to hydroxyapatite and then adding sodium fluoride thereto. A further article, "Orthophosphates. Part II. The Transformations Brushite.fwdarw.Fluoroapatite and Monetite.fwdarw.Fluoroapatite in Aqueous Potassium Fluoride Solution," Duff, Journal of the Chemical Society, Section A, 1971, pages 33-38 describes the chemical transformation of secondary calcium orthophosphates into a potassium-containing fluorapatite.
Hydroxyapatite, which is a material containing calcium and phosphate, has been used to promote remineralisation of tooth enamel as in U.S. Pat. No. 3,679,360, patented July 25, 1972 by Rubin and Childress, assignors to the United States of America, as represented by the Administrator of the National Aeronautics and Space Administration. In that patent, dicalcium orthophosphate dihydrate in a gel containing orthophosphate ions and a calcium salt, such as calcium nitrate, is applied to a damaged tooth and hydroxyapatite crystals are formed over a period of time.
It is an advantage of this invention that dental preparations are provided which contain calcium and phosphate components or moieties which provide desirable effects in the oral cavity such as controlled polishing or abrasivity, prophylactic advantages such as remineralisation, reduction of caries incidence or extent or reduction of bleeding from gums and cosmetic advantages such as increased white appearance of teeth.
It is a further advantage of this invention that novel and unique procedures are provided for preparing the desirable calcium and phosphate materials. Other advantages of the invention will be apparent from consideration of this specification.